Reshade/SFX creating screenshots in game folder

When I'm running Reshade/SweetFX then my game runs at 0 frames persecond, it's not frozen though, the game still reacts to input every 10 or so seconds. While this is happening Reshade/SweetFX is creating an unlimited amount of screenshots in the game's folder, I just had to delete 2GB worth of screenshots from my HL2 folder. Each screenshot was a 7MB big BMP file.

This happens with every version of Reshade/SweetFX and in every game I've tried so far.